Electrical connector and assembly

ABSTRACT

A heating element connector and assembly, particularly useful for electric cooking ranges, formed as a U-shaped female connector with folded-over internal wings for making spring contact with a terminal pin of the heating element laid therein. Said connector being captured in a dielectric housing which is slotted longitudinally and vertically to permit access of the terminal pin to the U-shaped connector and which housing is dimensioned to prevent over-stressing of the material of the connector.

United States Patent [72] Inventors Earl Earnest Folkenroth Harrisburg, Pa.; Barry John Dell, Norman, 0kla.; William Joseph Garver, Harrisburg, Pa. 1211 Appl. No. 813,927 [22] Filed Apr. 7, 1969 [45] Patented Oct. 12, 1971 [73] Assignee AMP Incorporated Harrisburg, Pa.

[54] ELECTRICAL CONNECTOR AND ASSEMBLY 13 Claims, 4 Drawing Figs.

[52] US. Cl 339/191 A, 339/258 P [51] Int. Cl H0lr 13/10 [50] Field of Search 339/191 A, 192 R, 221, 252, 256, 258 C, 258 P, 278 C, 258 F, 259 R, 259 F, 260

[5 6] References Cited UNITED STATES PATENTS 1,706,659 3/ 1929 Fahnestock 339/260 Re. 26,692 10/1969 Ruehlemann 339/258 P X Primary Examiner-Ian A. Calvert Attorneys-Curtis, Morris and Safford, Marshall M.

Holcombe, William Hintze, William J. Keating, Frederick W. Raring, John R. Hopkins, Adrian J. LaRue and Jay L. Seitchik ABSTRACT: A heating element connector and assembly, particularly useful for electric cooking ranges, formed as a U- shaped female connector with folded-over internal wings for making Spring contact with a terminal pin of the heating element laid therein. Said connector being captured in a dielectric housing which is slotted longitudinally and vertically to permit access of the terminal pin to the U-shaped connector and which housing is dimensioned to prevent over-stressing of the material of the connector.

ELECTRICAL CONNECTOR AND ASSEMBLY This invention relates to detachable electrical connectors and finds application in connecting Calrod-type surface burner units of an electrical range to the electric supply line.

The surface heating element of the modern electrical home cooking range is typically formed of a coil of resistance heating wire which is encased in a steel, tubular, protective jacket and separated therefrom by mineral insulation such as magnesium oxide. Exemplary of such a heating element is that manufactured by the General Electric Company under the trademark Calrod." Such heating elements usually are manufactured so that the nichrome wire terminates with a steel pin at either end to which the wire is permanently fixed. These steel pins are then utilized in the formation of detachable connections. Such pins may typically be made of solid cold rolled steel having a diameter of 0.091 inches. Although such pins are not as electrically desirable as would be a copper pin; they are, nevertheless, necessary because of the requirement for maintaining adequate mechanical properties at the high temperatures at which these surface burner unit elements operate.

In the past, effective detachable connections have been formed only through some permanent affixing of a separate member onto this terminal pin, such as by spot welding. This increases the complexity of design and manufacture of the resulting connection and decreases its reliability because of dependence upon the quality of the welding (or other joint) between such a member and the pin.

It is an object of the present invention to provide an electric range heating connector and assembly which is capable of reliably functioning under the rigors of temperature extremes and mechanical abuse occasioned by the frequent removal for cleaning of such surface burner heating elements by the ordinary retail consumer.

It is a further object of the present invention to provide such a quick-disconnect electrical connector which is of simple, and, therefore, economical construction, requiring low insertion force and yet providing an excellent electrical connection.

It is a still further object of the present invention to provide such a device in which the connection or the disconnection can be accomplished without requiring any particular care in alignment and still achieve all of the other objects of this invention.

One of the unique advantages of the present invention is the U-shaped female connector which is capable of making a highly reliable floating, wipe connection directly to the heater element terminal pin without the necessity of any second separate member of such connector being permanently affixed to the pin. This female connector is typically formed from flat steel stock folded up into a U-shape with the sides of the U folded back down into the well of the U. These internally folded arms, or wings, are folded back against the outer arm portions of the U to a degree sufficient to provide access for the terminal pin of the heating element therebetween and yet not so much as to prevent an inward spring action against the terminal pin. In order to assure sufficient and effective contact between the U-shaped female connector and the terminal pin, the arms of the U-shaped connector are transversely slotted substantially to the base of the U, thus, assuring multiple points of contact on the terminal pin should it be inserted into the U-shaped connector somewhat askew to the longitudinal extent of the connector.

In a further preferred embodiment of the present invention, this U-shaped female connector is captured within a housing having a V-shaped tapered lead-in positioned above the open end of the U of said connector and at least one vertical slot leading down from said lead-in along the end of the connector, whereby the terminal pin can be laid into said housing without particular attention to alignment or positioning, and the terminal pin will naturally slip down into the housing into effective connection with the internal wings of the connector held therein.

It is an advantage of the present invention that this internally winged U-shaped connector has such an open configuration which aids in heat dissipation such that although good electrical contact is made, it nevertheless has minimal thermal conductivity along the connector, and good heat dissipation from the connector. This is particularly advantageous in preventing the overheating of the lead wires (which being copper, readily conduct heat and could cause problems remote from the burner due to deterioration of the wire insulation and other elements in the proximity of such wires).

Other objects, advantages, and attainments of the present invention will become apparent to those skilled in the art upon reading of the following detailed description when taken in conjunction with the drawings in which there is shown and described a preferred embodiment of the invention; it is to be understood, however, that this embodiment is not intended to be exhaustive nor limiting of the invention, but is given for purposes of illustration in order that others skilled in the art may more fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use.

IN THE DRAWINGS FIG. 1 is an isometric view of a connector showing a preferred embodiment of the present invention;

FIG. 2 is an isometric view of a typical housing embodying a further aspect of the present invention which may be used with the connector illustrated in FIG. 1;

FIG. 3 is a vertical longitudinal section of the connector assembly on a range as though taken on lines 3-3 in FIG. 4, illustrating the inclusion of the connector of FIG. I in the housing of FIG. 2; and

FIG. 4 is a partial, vertical cross section of the housing and connector as though taken along lines 4-4 in FIG. 3.

The U-shaped female connector 10, illustrated in FIG. 1, comprises a floor 12 with upstanding sides 14. These sides I4 are folded back into the U-shape of the connector towards the floor 12 forming internal wings 16. The spacing between opposite wings 16 is slightly smaller than the terminal pin 18 of the heater element with which it makes connection (see FIG. 4).

It has been found that only a minimal contact force of the wings 16 against the terminal pin 18 is required in order to attain an effective electrical connection. An increase in the con tact force, by moving the wings closer together, or by other means, serves merely to increase the insertion force required without any meaningful improvement in the electrical properties of the connection. The ability of the connector 10 to make effective electrical connection with the terminal pin 18 with a very low insertion force enables the cooking range to be constructed in such a manner that the surface burner unit 20 can be positioned on the range 22 in the manner indicated in dotted outline and then merely by dropping the burner 20 by gravity into the position indicated in FIG. 3 (in full lines), the pin 18 will pivot on bracket 23 up onto place in the housing 24 into the connector 10 within the housing 24.

The connector 10 includes the internal wings 16, because applicants have discovered that without them a simple U- shaped connector'would require an insertion force which is too great, resulting in an overstressing of the metal, causing it to take a set, particularly at the elevated temperatures at which the burners 20 operate, resulting in a loose and ineffective connector. Furthermore, a simple U-shape would tend to expel the terminal pin and not grip it properly.

Any of a number of different kinds of terminating means 26 can be used to join the connector 10 to the wire lead 28 from the electric source. In the illustrated embodiment, this terminating means 26 has been shown as a wire barrel type solderless crimp connector. This crimp connector 26 has been formed as an extension of floor 12. When crimped onto the wire lead 28, the cars 30 wrap around the wire insulation as an insulation support and the arms 32 fold over back-to-back in a pressure crimp, digging into the electric wire of the lead 28.

FIG. 2 shows a preferred embodiment of a housing 24 which may be used to contain and insulate the connectors from the surrounding environment. This may typically be made from a phenolic resin. The housing illustrated in FIG. 2 is intended to hold two connectors 10. The connector assembly 8 in this preferred embodiment is completed by the insertion of a connector 10 through the vestibule 34 in the back end of the housing 24 and into the connector chamber 36 in the front part of the housing 24. The connector 10 is retained within the connector chamber 36 by a tongue 38 which is laneed out of the floor 12 of the connector 10 and is sprung outwardly so as to snap in behind the raised retaining bar 40. Once the connectors 10 are in place, the vestibule portion 34 of the housing 24 can be potted according to the standard electrical underwriters requirements. The housing 24 has several external recesses which are incorporated into its design to save on material, and, thereby, reduce the cost, but more importantly to aid in the circulation of air around the connectors and enhance heat dissipation. The housing illustrated in FIG. 2 has been designed to hold two connectors, since a pair of connectors is typically required in order to complete a circuit for an individual heating coil. The outer recesses 42 on either side of the housing 24 each have an ear 44 placed in opposing rearward corners of the recess 42. This means that if two housings 24 are ganged side by side, the cars 44 will fit into the opposing recess 42 to aid in their proper alignment. Similarly, the distance between the slots 46 of a given housing 24 is twice the distance between the slot 46 and its outermost adjacent side; so that when two or more housings 24 are ganged, the slots 46 on adjacent housings will have the same spacing as the slots of a given housing.

As shown in FIGS. 3 and 4, the terminal pin 18 makes connection with the connector 10 within the housing 24 by entering the longitudinal slot 48 guided by the tapered sides 50. When in position, the terminal pin 18 may come to rest anywhere along the parallel extent of the wings 16 and extend out of the housing 24 through the vertical slot 46.

One of the problems encountered in developing this connector was an overstressing of the wings 16 or the sides 14 beyond the yield point of the metal resulting in their taking a permanent set. This was particularly apt to happen when the burner was in use due to the inevitable presence of a large amount of heat from the closely adjacent burner. This overstressing would result in a loose fit which in turn would result in a poor connection. The large wattage required to heat a typical surface burner requires a large amperage through the connection. Therefore, a poor connection will have high resistance and result in overheating to the extent where actual spot welding of the wings 16 to the sides 14 could occur and cause the connector to fail altogether. Applicants discovered the source of this problem and found that by carefully designing the size of the connector chamber 36 with the respect to the sides of the connector 10, the outward flexing of the sides 14 could be physically restricted to an extent sufficient to prevent overstressing. A similar result was obtained by forming a longitudinal inward fold 52 at the base of the sides 14, just above the floor l2, and just above the free ends of the Wings 16. This fold 52 acts as a stop for the wings l6, preventing their being flexed too far outwardly. Thus, upon the insertion of the terminal 'pin 18 into the connector 10 it initially bears upon the portion of the wings 16 attached to the sides 14 forcing the sides 14 to flex outwardly. As the pin 18 descends along the Wings 16, the sides 14 continue to flex outwardly until the internal sides of the housing 24 within the connector chamber 36 are encountered. Also, as the pin descends it bears on the wings 16 more and more, remote from its joinder with the side 14, thereby enabling them to flex to a greater degree. If the pin 18 is properly aligned with the connector 10, it can descend all the way down to the free ends of the wings 16 without being stopped by the folds 52. However, if the pin 18 should be inserted slightly askew, the stop 52 prevents the wing 16 from being overstressed.

One of the major advantages of this connector is its ability to make an effective electrical connection with the terminal pin 18 within a relatively wide range of positioning. In other words, the pin may come to rest anywhere along the parallel extent of the wings 16 and may be slightly askew to the side or up-and-down or a combination of both without afi'ecting the quality of the electrical connection. It was found that this ability was enhanced by splitting the wings l6 and the effective portion of the sides 14, vertically on each side of the connector 10 into at least two separate portions by a slot 54. By this means, a connector such as illustrated in FIG. 1 would have four separate wings 16 to bear upon a terminal pin 18 and would make at least four separate points of contact on any terminal pin 18 positioned askew within the connector. It is within the scope of the invention to have more than two portions per side, but in the preferred embodiment this was not found to be necessary.

A typical example of the embodiment illustrated in FIGS. 1 to 4 would have the following dimensions. For use with a terminal pin 18 having a diameter of 0.091 inches and typically made from either cold rolled steel or stainless steel, the connector 10 could have a length of 0.6 inches (excluding the wire barrel crimp termination, or 0.94 inches including it), a width of 0.23 inches and a height of 0.4 inches. The housing 24 for such a connector 10 would have overall dimensions of 1.124 by 1.55 by 0.76 inches. The connector 10 would typically be made from an ordinary steel which is nickel-plated for lower wattages and would be silver-plated for wattages above 2,000 watts.

What we claim is:

l. A female electrical connector for mating with a pin termination comprising a floor, upstanding substantially straight sides forming a U-shape with said floor, internal wings curved over from the upper part of each of said sides into said U- shape and back down toward said floor with the major portion of each wing being substantially parallel to each other, said wings being spaced from one another by a distance slightly less than the diameter of said pin termination, a terminating means for joining said connector to an electric wire, first antistress restraining means constructed to permit said sides to spring out sufficiently to accept said pin termination and to restrict the outward movement of said sides sufficiently to prevent their overstressing, and second antistress restraining means for said wings for preventing their overstressing as said pin termination descends into said connector.

2. A female electrical connector for mating with a pin termination comprising a floor, upstanding straight sides forming a U-shape with said floor, internal wings curved over from the upper part of each of said sides into said U-shape and back down toward said floor with the major portionof each wing being parallel to said sides, said wings being spaced from one another by a distance slightly less than the diameter of said pin termination, each wing and most of its side being divided longitudinally into multiple portions by a vertical slot, said wings terminating towards said floor in free ends, and said sides hav ing an antioverstress restraining means formed as a longitudinal raised ridge extending inwardly toward said wings adjacent their free ends.

3. A connector as claimed in claim 2 wherein said connector is formed from flat metal stock and said restraining means is a longitudinal fold in each of said sides near said floor projecting inwardly to act as a stop beyond which said wings cannot be flexed.

4. A connector assembly device comprising a female electrical connector for mating with a pin termination; said connector further comprising a floor, upstanding sides forming a U- shape with said floor, internal wings curved over from the upper part of each of said sides into said U-shape and back down toward said floor with each wing substantially parallel to said sides, said wings being spaced from one another by a distance slightly less than the diameter of said pin termination, and a terminating means for joining said connector to an electric wire; and a dielectric housing having means carrying said connector internally with the floor of said connector positioned longitudinally; said housing having a longitudinal slot providing access to the longitudinally opened portion of the U-shape of said connector carried therein; and also a vertical slot coinciding with an open end of said connector and intersecting said longitudinal slot; said housing slots being wide enough to accept said pin termination.

5. A device as claimed in claim 4 for use as a high-temperature, high-amperage connector assembly wherein said connector is made from an electrically conductive material capable of maintaining its mechanical properties at elevated temperatures including functioning as a connector without overstressing the material beyond the yield-point.

6. A device as claimed in claim 4 wherein said housing is constructed to permit said sides to spring out sufficiently to accept said pin termination and to restrict the outward movement of said sides sufficiently to prevent their overstressing and said wings similarly have restraining means preventing their overstressing as said pin termination descends into said connector.

7. A device as claimed in claim 6 wherein said connector is made from steel and said restraining means is a longitudinal fold in each of said sides near said floor projecting inwardly to act as stop beyond which said wings cannot be flexed.

8. A device as claimed in claim 7 wherein said longitudinal slot in the housing is beveled to provide a taper lead-in to said connector and said housing carries a second connector beside said first, similarly housed.

9. A device as claimed in claim 8 wherein the spacing between the connectors is twice the spacing from each connector to the respective side of the housing whereby a plurality of housings may be ganged side-by-side and maintain equal spacings between connectors.

10. A device as claimed in claim 7 wherein said longitudinal slot is beveled to provide a taper lead-in to said connector, said tenninating means is a solderless connector formed from an extension of said floor at the end opposite said vertical slot in said housing, the floor has a tongue lanced and sprung out and pointing toward said terminating means, said housing forms a pocket for capturing said connector with said pockets open end opposite said housings vertical slot, the side of said pocket opposite said longitudinal slot having a raised lip positioned transversely to catch said tongue and retain said connector positioned within the housing.

11. A device as claimed in claim 10 wherein the sides of the connector near their ends joined to said wings abut the corresponding sides of said housing pocket, said raised lip in the side of said pocket opposite said longitudinal slot is formed by a trough the sides of which trough capture said torque transversely and the end of which trough forms said raised lip and captures the free end of said tongue in the longitudinal direction, the floor of said connector and its adjacent sides are slightly smaller in width than said pocket and are centrally positioned within said pocket by said tongue and trough.

12. A device as claimed in claim 4 wherein said longitudinal slot in the housing is beveled to provide a taper lead-in to said connector and wherein said vertical and longitudinal slots are only slightly wider than said pin termination such that adjacent said slots only said wings are exposed and the taper from said housing leads smoothly into the space between said wings without obstruction.

13. A device as claimed in claim 12 wherein the vertical slot formed in said housing has a longitudinal depth substantially greater than the width of said vertical slot sufficient to prevent severe skew orientation of said termination pin within said connector assembly device. 

1. A female electrical connector for mating with a pin termination comprising a floor, upstanding substantially straight sides forming a U-shape with said floor, internal wings curved over from the upper part of each of said sides into said U-shape and back down toward said floor with the major portion of each wing being substantially parallel to each other, said wings being spaced from one another by a distance slightly less than the diameter of said pin termination, a terminating means for joining said connector to an electric wire, first antistress restraining means constructed to permit said sides to spring out sufficiently to accept said pin termination and to restrict the outward movement of said sides sufficiently to prevent their overstressing, and second antistress restraining means for said wings for preventing their overstressing as said pin termination descends into said connector.
 2. A female electrical connector for mating with a pin termination comprising a floor, upstanding straight sides forming a U-shape with said floor, internal wings curved over from the upper part of each of said sides into said U-shape and back down toward said floor with the major portion of each wing being parallel to said sides, said wings being spaced from one another by a distance slightly less than the diameter of said pin termination, each wing and most of its side being divided longitudinally into multiple portions by a vertical slot, said wings terminating towards said floor in free ends, and said sides having an antioverstress restraining means formed as a longitudinal raised ridge extending inwardly toward said wings adjacent their free ends.
 3. A connector as claimed in claim 2 wherein said connector is formed from flat metal stock and said restraining means is a longitudinal fold in each of said sides near said floor projecting inwardly to act as a stop beyond which said wings cannot be flexed.
 4. A connector assembly device comprising a female electrical connector for mating with a pin termination; said connector further comprising a floor, upstanding sides forming a U-shape with said floor, internal wings curved over from the upper part of each of said sides into said U-shape and back down toward said floor with each wing substantially parallel to said sides, said wings being spaced from one another by a distance slightly less than the diameter of said pin termination, and a terminating means for joining said connector to an electric wire; and a dielectric housing having means carrying said connector internally with the floor of said connector positioned longitudinally; said housing having a longitudinal slot providing access to the longitudinally opened portion of the U-shape of said connector carried therein; and also a vertical slot coinciding with an open end of said connector and intersecting said longitudinal slot; said housing slots being wide enough to accept said pin termination.
 5. A device as claimed in claim 4 for use as a high-temperature, high-amperage connector assembly wherein said connector is made from an electrically conductive material capable of maintaining its mechanical properties at elevated temperatures including functioning as a connector without over-stressing the material beyond the yield-point.
 6. A device as claimed in claim 4 wherein said housing is constructed to permit said sides to spring out sufficiently to accept said pin termination and to restrict the outward movement of said sides sufficiently to prevent their overstressing and said wings similarly have restraining means preventing their overstressing as said pin termination descends into said connector.
 7. A device as claimed in claim 6 wherein said connector is made from steel and said restraining means is a longitudinal fold in each of said sides near said floor projecting inwardly to act as stop beyond which said wings cannot be flexed.
 8. A device as claimed in claim 7 Wherein said longitudinal slot in the housing is beveled to provide a taper lead-in to said connector and said housing carries a second connector beside said first, similarly housed.
 9. A device as claimed in claim 8 wherein the spacing between the connectors is twice the spacing from each connector to the respective side of the housing whereby a plurality of housings may be ganged side-by-side and maintain equal spacings between connectors.
 10. A device as claimed in claim 7 wherein said longitudinal slot is beveled to provide a taper lead-in to said connector, said terminating means is a solderless connector formed from an extension of said floor at the end opposite said vertical slot in said housing, the floor has a tongue lanced and sprung out and pointing toward said terminating means, said housing forms a pocket for capturing said connector with said pocket''s open end opposite said housing''s vertical slot, the side of said pocket opposite said longitudinal slot having a raised lip positioned transversely to catch said tongue and retain said connector positioned within the housing.
 11. A device as claimed in claim 10 wherein the sides of the connector near their ends joined to said wings abut the corresponding sides of said housing pocket, said raised lip in the side of said pocket opposite said longitudinal slot is formed by a trough the sides of which trough capture said torque transversely and the end of which trough forms said raised lip and captures the free end of said tongue in the longitudinal direction, the floor of said connector and its adjacent sides are slightly smaller in width than said pocket and are centrally positioned within said pocket by said tongue and trough.
 12. A device as claimed in claim 4 wherein said longitudinal slot in the housing is beveled to provide a taper lead-in to said connector and wherein said vertical and longitudinal slots are only slightly wider than said pin termination such that adjacent said slots only said wings are exposed and the taper from said housing leads smoothly into the space between said wings without obstruction.
 13. A device as claimed in claim 12 wherein the vertical slot formed in said housing has a longitudinal depth substantially greater than the width of said vertical slot sufficient to prevent severe skew orientation of said termination pin within said connector assembly device. 